Enclosed circuit interrupter



March 9, 1943. L. PIERCE ENCLOSED C IRCUIT INTERRUPTER Filed July 20, 1940 4 Sheets-Sheet 1 March 9, 1943. 1.. PIERCE ENCLOSED CIRCUIT INTERRUPTER Filed July 20, 1940 4 Sheets-Sheet 2 INVENTOR Law/'epcefizrw ATTM WITNESSES: &%m

March 9, 1943. PlERCE 2,313,170

ENCLOSED C IRCUIT INTERRUPTER Filed July 20, 1940 4 Sheets-Sheet 3 WITNESSES: INVENTOR March 9, 1943. L. PIERCE 2,313,170

ENCLOSED CIRCUIT INTERRUPTER Filed July 20, 1940 4 Sheets-Sheet 4 INVENTOR law/ma??? Patented Mar. 9, 1943 ENCLOSED CIRCUIT INTERRUPTER Lawrence Pierce, Pittsburgh, Pa-., .assignor to fwestinghouse Electric 80 Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application July 20, 1940, Serial No. 346,530

20 Claims.

The invention relates to electrical switches or circuit breaker mounted in metal casings, and more particularly to devices for operating and locking such switches or circuit breakers.

The usual type of enclosed switch or circuit breaker has some form of lugs provided with holes for receiving padlocks to lock the operating handle in'the off position. The constructions, however, have the disadvantage that it is possible to insert a padlock when the switch is in a closed circuit position. Similarly, in the case of constructions having multiple holes or slots for receiving several padlocks, these holes can be lined up so that a padlock can be inserted when the switch is in closed position. This is a dangerous condition for the reason that a person, unfamiliar with electrical switches, who is directed to lock a switch oil may hang a padlock with the switch in on" position thinking that he has locked it off. The same dangerous condition i present to an even greater extent where the switch or circuit breaker is of the type embodying a snap action mechanism, for in many of these types the operating handle must be moved through the major portion of its throw or almost to the full ofi position before the snap action mechanism passes overcenter and becomes effective to open the contacts. In such case a person may even move the handle toward "01? position and insert a padlock without having opened the contacts.

The copending application of Gilbert Currie, Serial No. 212,874, filed June 10, 1938, and assigned to the assignee of the present invention, now Patent No. 2,263,760, dated November 25, 1941, discloses and claims an enclosed switch or circuit breaker embodying one form of locking device which obviates the above described dangerous condition by providing a handle assembly having provision for receiving several padlocks and arranged so that a padlock can be inserted only when the handle is in the full off position. The present invention is a further development of features of the above mentioned copending application, and covers a different construction of locking device which is simpler and less expensive to manufacture than that disclosed in the aforementioned application.

An object of the invention is the provision of an enclosed switch or circuit breaker embodying an improved handle locking device having provision for receiving several padlocks and constructed and arranged so that a padlock can be inserted only when the switch is ofilf Another object of the invention is the provision of an enclosed circuit interrupter having a snap acting mechanism and an operating handle wtih a locking device associated therewith having a plurality of holes or slots for receiving several padlocks and constructed and. arranged so that a padlock can be inserted only when the contacts of the interrupter are in full off position and the handle is in off position.

Another object of the invention is the provision of an enclosed circuit interrupter with an improved handle locking device which is simple, comprising a minimum number 01' parts, and which is inexpensive to manufacture.

In accordance with the invention the enclosed circuit interrupter embodies a handle locking device comprising two nesting cups or cylinders, one rigid with the operating handle and the other non-rotatably secured to the enclosing casing so that they are disposed in concentric relation to the axis of rotation of the handle. Each cup is provided with a plurality of openings identical to the openings of the other for receiving the hasp of an ordinary padlock and located so that they exactly line up only when the operating handie is in off" position. The angular spacing of the holes in each cup'must be more than the total angular throw of the operating handle. This makes the holes such that when the handle is in any other position than an off position, the holes in one cup are always disposed opposite a solid section of the other cup and a lock cannot be inserted.

The novel features that are considered characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to structure and operation, together with additional objects and advantages thereof will be best understood from the following detailed description of several embodiments thereof when read in conjunction with the accompanying drawings in which:

Figure 1 is a plan .view of an enclosed switch embodying the feature of the invention, part of the cover being broken away to show the switch mechanism, the switch being in the on" position Fig. 2 is a fragmentary sectional view taken substantially along the line lI--I[ of Fig. 1 showing the snap action mechanism;

Fig. 3 is a fragmentary sectional view taken along the line III-III of Fig. 2 and looking in the direction of the arrows;

Fig. 4 is an exploded perspective view of'the handle assembly;

Fig. 5 is a fragmentary side elevational view handle in the 011" position,

Fig. 9 is a perspective view of a modified handle construction, and

Fig. 10 is a fragmentary plan view of the casing showing a cover locking device which may be added if desired.

Referring to the drawings, the enclosure for the switch comprises a sheet metal casing having side, end and bottom walls, and having a cover l3 pivotally attached to one of the side walls by a pair of hinges I5, the cover being provided with a peripheral flange I! which overlaps the edges of the side and end walls.

A multipole switch mechanism is mounted in the casing and comprises an insulating base l9 upon which is mounted a plurality of hinged jaws 2| and contact jaws 23 for receiving a plurality of switch blades 25 that are pivoted to the hinged jaws at 21. Each switch blade 25 and its hinge and contact jaws 2| and 23 constitute one pole of the switch. The contact jaws 23 are provided with terminals 23 and the hinge jaws with terminals 3|. If desired, each pole of the switch may be provided with a fuse 33 mounted in alignment with its corresponding switch blade and electrically connected in series therewith.

The switch blades 25 are of the knife blade type and are adapted to be simultaneously actuated by means of a bail 35 which constitutes a crank that is "pivoted at its opposite ends to the side walls of the casing Each switch blade is mechanically connected to the bail or crank 35, and insulated therefrom, by means of a hook-shaped clamp 31 of. insulating material. One end of "the crank 35 is rotatably mounted in a bearing 33 on one of the side walls of the casing I and the opposite end of the crank is rotatably mounted in a tubular bushing or bearing 4| (Fig. 3) which is mounted on the opposite side wall of the casing in alignment with the bearing 38.

A snap action mechanism indicated generally at 43 is associated with the crank or bail 35 adjacent one end thereof for causing the switch blades to be actuated to open and to closed circuit positions with a snap action when the switch is operated. The snap action mechanism comprises an actuating member 45 rotatably mounted on the bushing 4|, and a pair of oppositely disposed overcenter spring units 41 which engage the rotatable actuator 45 at diametrically opposite points.

The actuating member 45 (Figs. 2, 3 and 4) comprises a pair of spaced plates 43 and rigidly secured together in slightly spaced relation by a pair of spacer pins 53, the ends of which are riveted over against the plates. The plates 49 and 5| are provided with a central opening in which is mounted a bearing sleeve 55 bymeans of which the actuating member 45 is rotatably mounted on the bushing 4|. The actuating member 45 has a lost motion connection with the crank 35 and for this purpose the inner plate 49 of the member 45 is provided with an angular extension 51 having a pair of spaced arms 59 adapted to engage the opposite 75 sides of the bent portion of the crank 35. The actuating member is, in turn, adapted to be manually oscillated by means of an operating handle mounted on the outside of the casing, which will hereinafter be described. The op erating handle is provided with a driving element which extends through a slot in the side of the casing and engages a slot 3| formed in the plate 5| oi the actuating member 45. The slot 5| provides a lost motion connection between the operating handle and the actuating member 45.

Each overcenter spring unit 41 comprises an actuating fork 53 and a coil spring 55 which is mounted on the arm of the fork 53 and disposed in compression between the head of the fork and an angle-shaped guide bracket 61. The guide bracket 51 is pivotally mounted on the side wall of the casing II by means of a pivot stud 53, and the angularly projecting end of the bracket 51 is provided with an opening through which the outer end of the fork arm extends. The heads ll of the actuating forks 53 pivotally engage the pins 53 of the actuating member 45 between the plates 43 and 5|.

When the actuating member 45 is rotated in either direction by the operating handle, the

springs 55 are compressed during the first portion of the movement and as soon as the connecting pins 53 cross the line joining the fixed pivots 59 of the springs, the line of action of the springs is shifted, so that the springs act to continue the movement of the actuating member from this point on with a snap action. The arms 53 of the actuating member 45 are preferably spaced apart a sumcient distance so that they engage and begin to move the crank 35 approximately at the point when the springs 55 pass overcenter.

An interlock is provided for preventing opening of the cover except when the switch is in off position and also for preventing closing of the switch when the cover is open. This interlock comprises an interlock lever 13 (Fig. 2) having an oflset inner end 15 which pivots in an opening 11 provided in the side wall of the casing The interlock lever 13 is biased in a clockwise direction by means of a compression spring 13 interposed between the projection 5| of the interlock lever and the bottom wall of the casing The outer end 53 of the interlock lever cooperates with a spring pressed latch 55 mounted on the inside of the cover |3 of the casing. The interlock lever 13 is operated in accordance with the position of the operating handle of the switch by means of a cam plate 81 which moves with the operating handle and which is rotatably mounted on the bushing 4| between the actuating member 45 and the side wall of the casing The cam plate 51 is connected for movement with the operating handle by means of a slot 33 therein which engages the driving element of the operating handle. The interlock lever I3 is provided with an arcuate edge 9| which rides on the periphery of the cam plate 51 and the cam plate is provided with a notch 93 which is positioned opposite the arcuate edge 5| of the interlock lever when the operating handle is in the off position, so as to permit opening of the cover when the operating handle is in "053 position. The cover when in closed position bears against the end of the interlock lever and prevents the edge 9| from dropping into the notch 33. As the cover is opened the interlock lever is rotated a small distance in a clockwise direction by the spring 19 so that the arcuate edge 9I seats in the notch 93 of the cam plate 91, and the free end 93 clears the latch 95. In this position the interlock lever 13 functions to prevent closing of the switch as long as the cover is open.

The switch mechanism described above is similar to that disclosed in the copending application of J. W. Samzelius, Serial No. 346,528, filed July 20, 1940, and assigned to the assignee of the present invention, now Patent No. 2, 76,006, granted March 10, 1942.

The operating handle 94 of theswitch comprises an operating lever 95, a driving element 91, and a cup-shaped locking element 99 I all secured to rotate as a rigid unit on the bushing H at the putside of the casing II. The cupshaped locking element 99 cooperates with a fixed locking cup IDI secured to the wall of the casing to provide a means for locking the switch and handle in off" position, as will be described hereinafter.

The fixed locking cup I9I has a centrally disposed tubular sleeve I03 which fits snugly in an opening provided therefor in the side wall of the casing II, and the bushing 4| extends through the sleeve I93 and is provided with a shoulder I95 which bears against the locking cup I! to retain it in mounted position. A cotter key I91 engages an annular slot on the inner end of the bushing 4| to maintain the actuating member 45 and the cam plate 81 in mounted position on the bushing 4| and also cooperates with the shoulder I95 of the bushing to maintain the locking cup IIII and the bushing in assembled position on the casing. The locking cup II is provided with an integral projection I09 which extends through an opening in the wall of the casing, and this projection cooperates with a pair of shoulders I I I and I I3 formed on the actuating member 45 to limit movement of the actuating member 45 in both directions.

The offset inner end of the handle lever 95, the driving element 91. and the central portion of the cup-shaped locking element 99 are each provided with a, circular opening by means of which these elements are rotatably mounted on the outer portion of the bushing 4|. The handle lever 95 extends through an opening II5 provided therefor in the peripheral flange of the cup-shaped locking element and this opening fits the lever snugly so that the handle lever 95 and cup-shaped locking element 99 are rigidly coupled for rotation together.

The driving element 91 is mounted on the bushing 4| between the inner end of the handle lever 95 and the cup-shaped locking element 99 and is provided with an angularly bent driving projection II! which fits snugly in a notch 98 (Figs. 5 and 6) provided therefor in the inner end of the handle lever 95 so that the driving element is thereby rigidly coupled to the handle lever for rotation therewith. The driving projection I I1 extends through aligned are late slots H9 and HI formed in the fixed locking cup and in the wall of the casing II and also passes through the close fitting slot 89 of the rotatable cam plate 81. The inner end of the driving projection engages in the arcuate slot 6| of the snap-acting actuating member 45. The parts 95, 91 and 99 of the switch operating handle are retained in mounted position on the bushing 4| by riveting over the outer end of the bushing 4| adjacent the cup-shaped locking element 99 as shown in Fig. 3. V

The operation of the switch is briefly as follows: The switch mechanism and operating handle are shown in the on or closed-circuit position in Figs. 1, 2, 3 and 6. To operate the switch to the off or open-circuit position, the operating handle 94 is manually moved downwardly. that is to say, in a counterclockwise direction to the ofi" position shown in Fig. 5. The driving element 91 and the cup-shaped locking element 99 move as a rigid unit with the operating lever 95, and as soon as the lost motion provided by the slot BI is taken up the driving element 91 moves the snap-acting actuating member 45 in a counterclockwise direction with the operating handle. The crank 35 and switch blades 25 however, remain in the on position during the first portion of the movementof the actuating member 45 until approximately the time that the overcenter spring units 41 pass overcenter. This is due to the lost motion connection between the crank 35 and the actuating member 45 provided by the spaced arms 59 of the actuating member. As soon as the overcenter spring units 41. pass overcenter, the actuating member 45 is moved with a snap action from this point on to the full off position where it is stopped by the shoulder III thereof engaging the stop projection I09. Approximately at the time the spring units 41 begin to pass overcenter the trailing arm 59 of the actuating member 45 engages the crank 35 so that this crank and the switch blades 25 are moved with a snap action to the full off position by the actuating member 45 and spring units 41. By reason of the slot 5i it is impossible to check the snap acting movement of the switch mechanism once this movement is started, since the actuating member is moved ahead of the handle by the overcenter springs as soon as they pass overcenter.

In operating the switch to the on position substantially the reverse operation takes place. The operating handle 94 is manually moved in a clockwise direction to the on position shown in Figs. 1, 2, 3 and 6. As soon as the spring units 41 have been moved overcenter, the force of the springs acts to move the actuating member 45 and the switch blades 25 to the on position with a snap action.

A pair of stops I23 on a bracket I25 secured to a side Wall of the casing are adapted to be engaged by the crank 35 in the on and oil" positions of the crank to take up the shock of the moving parts and to limit the movement of the crank.

In accordance with the invention, the fixed locking cup IM and the cup-shaped locking element 99 cooperate to provide a means for locking the switch and operating handle in the off position. For this purpose the fixed locking element IOI has a cylindrical flange I21 disposed concentric to the axis of rotation of the operating handle and provided with a plurality of spaced slots or openings I29, each of suflicient size to receive the hasp of a padlock. The central portion of the cup-shaped locking element 99 is depressed so as to provide a circular rim or flange I3I which has a U-shaped cross section as shown in Fig. 3. The cup-shaped locking element 99 is disposed in nesting relation with the fixed locking cup IllI so that the periphery of the flange I3I of the cup-shaped locking element 99 overlies the flange I21 of the fixed looking cup IBI. The flange I3| of the cup-shaped locking element 99 is provided with a plurality of spaced openings I33, each of just sufiicient size to receive the hasp of a padlock. The openings I33 of the cup-shaped locking element 99 and the opening I29 of the flied locking element IIlI are equally spaced and arranged so that they exactly line up when the opening handle 34 is in the full ofi position such that the hasp of a padlock can be inserted through each pair of lined up openings I29 and I33 to lock the operating handle in the full off position. The angular spacing of the openings I29 and the openings I33 of each cup is made more than the total angular throw of the operating handle 94 so that when the operating handle is in any other position than the ofi position the openings of one cup are disposed opposite a'solid section of the other cup and a padlock cannot be inserted. In the embodiment of the inven-' tion illustrated in Figs. 1 to 6, three openings are provided in each locking element and these openings are angularly spaced 120 apart, the angular throw of the operating handle being less than 120. The arrangement permits the use of as many padlocks as the complete circle of 360 divided by slightly more than the angular throw of the operating handle permits, and still at no time does any opening line up with any other opening except in the off position of the op, eratinghandle.

Fig. 5 shows the operating handle 34 in the full 011" position. In this position the openings I33 of the cup-shaped locking element 99 are exactly lined up with the openings I29 of the fixed locking cup IOI, so that one or more padlocks can be inserted to lock the switch in off" position. When the operating handle 94 is in any other position than the full 011" position; a padlock cannot be inserted since the openings of one cup are disposed opposite solid section of the other cup. Fig. 6 shows the operating handie in the on position, and in this position each lock opening is disposed opposite a solid section of the other locking cup so that it is impossible to insert a padlock.

A modification of the invention is illustrated in Figs. '7 and 8. In Figs. 7 and 8 the same reference characters with a prime mark are used to designate the elements which correspond to those of the original embodiment. In this modification the cup-shaped locking element 99' is provided with openings I35 and I31, and the fixed locking cup IOI is provided with identical openings I39 and MI. The openings I35 and I39 are of just sufiicient size to receive the hasp of a. single padlock. The openings I31 and Ill, however, are made of sufiicient size to receive the hasps of two padlocks. Thus the switch can be locked in the ofi" position by the insertion of one, two or three padlocks. The openings of the cup-shaped locking element 99' and the openings of the fixed locking cup IUI are spaced apart a greater distance than the throw of the operating handle 94 and arranged so that they line up exactly when the handle is in the full "off position. The throw of the operating handle 94' in this modification is made slightly greater in an opening direction than the throw of the operating handle 94 of the original embodiment, and the arrangement is such that a padlock cannot be inserted except when the handle is in an ofi position such that the switch mechanism is in the full off position. Although the openings I31 and I ll may be partially lined up a sufiicient amount when the handle is near the full ofi" position to permit the insertion of a padlock therethrough, the construction is such that the switch mechanism will be in the full ofi" position whenever these openings are lined up a sufllcient amount to permit the insertion of a padlock. Thus it is impossible to insert a padlock except when the switch mechanism is in the full 011" position.

A further modification of the invention is shown in Fig, 9. In this modification the operating handle I45 of the switch is formed as a single integral element having a handle lever portion I41 and an integral cup-shaped locking portion I49 having a plurality'of spaced padlock receiving openings I5I arranged in the same manner as the lock openings of the original embodiment shown in Figs. 1 through 6. The operating handle I45 has a driving element I53 rigidly secured thereto for operating the switch mechanism. The remaining construction of the switch mechanism and the fixed locking cup on the casing are identical to the embodiments shown in Figs. 1 through 6.

It will be noted that in all of the embodiments of the invention previously described a padlock cannot be hung or inserted anywhere on the casingv without looking the switch foff. This makes the enclosure switch absolutely safe. It is, therefore, desirable not to have any other place on the casing where a padlock can be hung except in the handle locking device. However, in those cases where it is desired to lock the cover closed to prevent unauthorized entry into the casing a cover locking device may be added as shown in Fig. 10. Referring to Fig. 10 the cover locking device comprises a latch I51 which is pivoted at I58 to the side wall of the casing II and has a latch nose I59 adapted to extend through a slot I5I in the cover I3, The latch is biased by a spring I63 to latching position in which the latch nose I59 engages over one end edge of the slot I6I. An ear I65 is secured to the cover I3, and this 'ear is provided with an opening I51 which aligns with an opening I69 in the projecting end of the latch I51 when the latch is in latching position. The cover I3 may be locked closed by inserting a padlock through the openings I61 and I59.

If desired a knockout may be provided in the flange of either the fixed locking element or the movable locking element in any of the previously described embodiments, such knockout being disposed to line up with one of the openings of the other locking element when the operating handle is in on position so that the switch may be locked by a padlock in the on position after removing the knockout. Such a knockout is indicated by the dotted line at I30 in Fig. 4.

For special applications a switch may be required which can be locked only in the on position by more than one padlock, instead of in the 011 position as previously described. This may be accomplished by the same elements of the invention previously described except that in such instance the locking holes of thefixed and movable locking elements would be disposed so as to exactly line up only when the operating handle is in on position.

The invention provides an enclosed circuit interrupter embodying an improved handle locking construction such that a padlock can be inserted only when the switch is in the full off position and such that several padlocks can be used to lock the, switch off. The construction is absolutely safe since it is impossible to hang or insert a padlock except when the switch is in the full oiP' position.

While the invention has been disclosed in accordance with the provisions of the patent statutes, it is to be understood that various changes in the structural details thereof may be made WithQLt/departing from some of the essential features of the invention. It is desired, therefore, that the appended claims shall be accorded the broadest reasonable construction consistent with their language and the prior art.

- I claim as my invention:

1 An enclosed circuit interrupter comprising an enclosing casing, circuit interrupter mechanism mounted in said casing, a movable operating handle on said casing for operating said interrupter, and handle' locking means comprising a fixed locking element on said casing and a cooperating locking element movable with said handle having provision for receiving one or more locks to lock said interrupter in off position and disposed so that a lock cannot be in- -a plurality of spaced openings disposed to line up when said handle is in oil position for receiving a plurality of locks, any one look when inserted through a lined up pair of said openings of said locking elements effecting locking of the interrupter in oil position, said locking elements and said openings being disposed so that a lock cannot be inserted through any one of said openings except when said handle is in a position such that the interrupter is in oil position.

6. An enclosed circuit interrupter comprising an enclosing casing, a circuit interrupter in said casing, an operating handle on said casing movable to on and off positions for operating said interrupter to on and oil positions, said handle having a locking portion which cooperates with a fixed locking means on said casing, said locking portion and said locking means each having a plurality of spaced openings disposed serted in either locking element except when the interrupter is in full ofi" position.

2. An enclosed circuit interrupter comprising an enclosing casing, circuit interrupter mechanism in said casing, an operating handle on said casing movable to -on and off positions for operating said interrupter, and handle locking means comprising a fixed locking element on said casing and a cooperating locking element movable with said handle, said elements having openings for receiving a padlock to lock said handle oif" and said openings being disposed so that a padlock cannot be inserted through any opening except when said handle is in a position such that the interrupter is in full ofl" position.

3. An enclosed circuit interrupter comprising an enclosing casing, a circuit interrupter in saidcasing, an operating handle on said casing movable to on and off positions for operating said interrupter to on and 0111 positions, handle locking means comprising a fixed locking element on said casing and a cooperating locking element movabl with said handle, said locking elements having openings for receiving several locks to lock said interrupter off, said openings being disposed so that a lock cannot be inserted through any opening except when the interrupter and handle are in ofl" position.

4. An enclosed circuit interrupter comprising an enclosing casing, a circuit interrupter in said casing, an operating handle on said casing movable to on" and off positions for operating the interrupter to on and off positions, handle locking means comprising a fixed locking element on said casing and a cooperating locking element movable with said handle, said looking elements having a plurality of cooperating openings for receiving several padlocks to lock said interrupter off, said openings being disposed so that all of the openings of each element lie opposite solid sections of the other for all positions of the handle except where the handle is in a position such that the interrupter is in off" position.

5. An enclosed circuit interrupter comprising an enclosing casing, a circuit interrupter in said casing, an operating handle on said casing movable to on and off positions for operating said interrupter to on and "off positions, means for locking said interrupter ofi comprising a fixed locking element on said casing and a cooperating locking element movable with said handle, said locking elements eachhaving to line up when said handle is in off" position for receiving a plurality of padlocks, any one padlock when inserted through a pair of lined up openings effecting locking of said handle and interrupter in oiI position, said openings being disposed so that a padlock cannot be inserted in any ofsaid openings except when said handle is in a position such that the interrupter is in off position.

7. An enclosed circuit breaker comprising an enclosing casing, a circuit interrupter in said casing, an operating handle rotatably mounted on said casing and movable to "on and oil positions for operating said interrupter to on and oil positions, a fixed locking element on said casing having a substantially cylindrical flange disposed concentric to the axis of rotation of said handle, said handle having a substantially cylindrical flange disposed in nesting relation with the flange of said locking element, said flanges each having a plurality of spaced openings which line up when saidhandle is in ofi position for receiving a plurality of padlocks to lock said interrupter off, said openings being disposed so that a padlock can be inserted only when said handle is in a position such that the interrupter is in off position.

8. An enclosed circuit interrupter comprising an enclosing casing, a circuit interrupter mounted in said casing, an operating handle on said casing movable to on and ofl positions for operating said interrupter to on and off positions, looking means for locking said interrupter oii comprising a fixed locking portion on said casing and a cooperating locking portion movable with said handle, said locking portions each having a plurality of openings spaced apart a greater distance than the throw of said handle so that the openings line up only when said handle is in off position for receiving a plurality of locks to lock the handle and interrupter off, said openings being disposed so that a lockcannot be inserted in any opening except when said handle is-in off position.

9. An enclosed circuit interrupter comprising an enclosing casing, a circuit interrupter in said casing, a rotatable operating handle on said casing movable to on and off positions for operating said interrupter to on and off positions, a fixed locking element on said casing having a substantially cylindrical flange disposed concentric to the axis of rotation of said handle, said handle having a substantially cylindrical locking flange disposed in nesting relation with the flange of said fixed locking element, said flanges each having a plurality of openings spaced apart a greater angucontacts, said handle being movable through a considerable portion of its throw before said snapacting mechanism actuates said contacts, looking means comprising a fixed locking element on said casing and a cooperating locking element movable with said handle, said elements each having a plurality of openings which line up when said handle is in off position for receiving a plurality of padlocks to lock said handle and interrupter off, said openings being disposed so that a padlock can be inserted only when said handle is in a position such that the contacts of the interrupter are in o position.

11. An enclosed circuit interrupter comprising an enclosing casing, circuit interrupter mechanism in said casing including relatively movable contacts and a snap-action mechanism therefor, a rotatable operating handle on said casing movable to on and off positions for operating said snap action mechanism to actuate said interrupter contacts to on and oil positions, said handle being movable through a considerable portion of its travel before said snap-action mechanism actuates said interrupter contacts, a fixed locking element on said casing having a substantially cylindrical flange concentric with the axis of rotation of said handle, said handle having a substantially cylindrical locking flange disposed in nesting relation with the flange of said fixed locking element, said flanges each having a plurality of openings which line up when said handle is in an oii position for receiving a plurality of locks to lock said interrupter off, said openings being disposed so that a lock can be inserted only when said handle is in an off position such that the interrupter contacts are in off position.

12. An enclosed circuit interrupter comprising an enclosing casing, a circuit interrupter in said casing including relatively movable contacts and a snap-acting mechanism therefor comprising a rotatable member for moving said contacts and spring means for causing snap-acting movement of said rotatable member, a rotatable operating handle on said casing movable to on and off positions for moving said rotatable member to actuate said contacts to on and ofi positions, a fixed locking element on said casing having a substantially cylindrical flange concentric with the axis of rotation of said handle, said handle havin a substantially cylindrical locking flange disposed in nesting relation with the flange of said locking element, said flanges each having a plurality of openings which line up when said handle is in an off position for receiving a plurality of padlocks to lock the interrupter off, said openings being disposed so that a padlock can be inserted only when said handle is in a position such that the interrupter contacts are in on position.

13. An enclosed circuit interrupter comprising an enclosing casing, a circuit interrupter in said casing, a rotatable operating handle on said casing movable to on and oil positions for operating said interrupter to "on and off positions,

' a fixed locking element on said casing having a substantially cylindrical flange concentric with the axis of rotation of said handle, said handle having a substantially cylindrical locking flange disposed in nesting relation withthe flange of said locking element, said flanges each having three spaced openings which line up with the openings of the other when said handle is in "of!" position for receiving padlocks to lock the interrupter off, the openings of each flange being spaced apart a greater distance than the throw of said handle so that a padlock can be inserted only when said handle is in 011" position.

14. An enclosed circuit interrupter comprising an enclosing casing, a circuit interrupter in said casing, a rotatable operating handle on said casing movable to on" and 011" positions for operating said interrupter to on and of! positions, a fixed locking element on said casing having a substantially cylindrical flange concentric with the axis of rotation of said handle, said handle having a substantially cylindrical locking flange disposed in nesting relation with the flange of said locking element, said flanges each having two openings which line up when said handle is in "off position for receiving padlocks to lock the interrupter off, the openings of each flange being spaced apart a greater distance than the throw of said handle so that a padlock can be inserted only when the handle is in a position such that the interrupter is off, and at least one of the openings of each flange being of suflicient size to receive the hasps of two padlocks.

15. An enclosed circuit interrupter comprising an enclosing casing, a circuit interrupter in said casing, an operating handle on said casing movable to full on and ofi operating positions for operating said interrupter to on and oil positions, handle locking means comprising a fixed locking element on said casing and a cooperating locklng element movable with said handle, said locking elements each having a plurality of locking openings which line up only when said handle is in one of said aforementioned operating positions for receiving several padlocks to lock said switch and handle in said one operating position, said openings being disposed so that a padlock can be inserted only when said handle is in said one operating position.

16. In an enclosed circuit interrupter, an enclosing casing, a circuit interrupter in said casing having relatively movable contacts, an operating handle on said casing movable to on and off positions for operating said interrupter to on and oiT positions, a snap-acting mechanism in said casing for causing said contacts to be actuated with a snap-action comprising a rotatable member for moving said contacts, said rotatable member having a lost motion connection with said handle and being movable by said handle, spring means engaging said rotatable member for imparting snap-acting movement to said rotatable member after said member has beenmovedapredetermined amount by said handle, handle locking means comprising a fixed locking element on said casing and a cooperating locking element movable with said handle, said locking elements each having a plurality of spaced openings which line up with the openings of the other when the handle is in off" position for receiving a plurality of padlocks to lock the interrupter ofi, said openings being disposed so that a padlock can be inserted only when the handle is in off position such that the interrupter contacts are in full ofi position.

17. In an enclosed circuit interrupter, an enclosing casing, a circuit interrupter in said casing having relatively movable contacts, a rotatable operating handle on said casing movable on and oil positions for operating said interrupter to "on and off positions, a snap-acting mechanism in said casing'for causing said contacts to be actuated with a snap-action, comprising a rotatable member rotatable about the same axis assaid' handle for moving said contacts, said rotatable member having a slot in which an element of said handle projects to provide a lost motion connection between said rotatable member and said handle, said handle being operable to move said rotatable member, spring means engaging said rotatable member for imparting snap-acting movement to said rotatable member when said member has been rotated a predetermined amount by said handle, handle locking means comprising a fixed locking element on said casing having a substantially cylindrical flange concentric with the axis of rotation of said handle and disposed in nesting relation with a substantially cylindrical locking flange of said handle, said flanges each having a plurality of spaced openings which line up when said handle is in off position for receiving a plurality of padlocks to lock said interrupter off, the openings of each flange being spaced apart a greater distance than the throw of said handle so that a padlock can be inserted only when the handle is in ofi position such that the interrupter is in full ofi position.

18. An enclosed circuit interrupter comprising an enclosing casing, a circuit interrupter in said casing, a rotatable operating handle on said casing movable to on and "oii positions for operating the interrupter to on and off positions, locking means comprising a locking element fixedly secured to said casing and having a substantially cylindrical flange concentric with the axis of rotation of said handle, said handle having a cooperating cup-shaped portion having a substantially cylindrical flange extending inwardly toward the casing and enclosing the flange of the locking element on said casing, said flanges each having an opening, the openings being disposed to line up when the handle is in off position for receiving a padlock to lock the interrupter o 19. An enclosed circuit interrupter comprising an enclosing casing, circuit interrupter mechanism in said casing, a rotatable operating handle on said casing movable to on and off positions for operating the interrupter to on and ofi positions, snap-acting mechanism between said circuit interrupter mechanism and said handle for actuating said interrupter with a snap action when said handle has been moved a predetermined amount from one operating position towards the other, and locking means comprising a cup-shaped locking element fixedly secured to said casing and having a substantially cylindrical flange concentric with the axis of rotation of said handle, and a cooperating cup-shaped element on said handle having a substantial cylindrical flange concentrically enclosing the flange of the cupshaped element on the casing, said elements each having a plurality of openings which line up when the operating handle is in oil position for receiving a plurality of padlocks to lock the interrupter 20. An enclosed circuit interrupter comprising an enclosing casing, circuit interruptermechanism in said casing having relatively movable contacts, a rotatable operating handle on said casing movable to on and off positions for operating said interrupter to on and all positions, snap-acting mechanism in said casing for causing said interrupter to be actuated with'a snap action, said snap-acting means comprising a rotatable member rotatable about the same axis as aid handle for actuating the interrupter, said rotatable member having spaced portions engageable by an element movable with said handle to provide a lost-motion connection between said rotatable member and said handle, said handle being operable to move said rotatable member, spring means engaging said rotatable member for imparting snap-acting movement to said rotatable member when said rotatable member has been rotated a predetermined amount by said handle, locking means comprising a cup-shaped locking element secured to said casing and having a substantially cylindrical flange concentric with the axis of rotation of said handle and disposed in nesting relation within a cooperating substantially cylindrical flange of said handle, said flanges each having a plurality of spaced openings whichline up when said handle is in ofi position for receiving a plurality of padlocks to lock said interrupter o LAWRENCE PIERCE 

